scholarly journals Fault diagnosis for satellite sensors and actuators using nonlinear geometric approach and adaptive observers

2018 ◽  
Vol 29 (16) ◽  
pp. 5429-5455 ◽  
Author(s):  
P. Baldi ◽  
M. Blanke ◽  
P. Castaldi ◽  
N. Mimmo ◽  
S. Simani
Keyword(s):  
Fault Diagnosis ◽  
Geometric Approach ◽  
Sensors And Actuators ◽  
Adaptive Observers ◽  
Satellite Sensors ◽  
Nonlinear Geometric

Computer Modeling of a Tire under Cornering Loads

1989 ◽  
Vol 17 (2) ◽  
pp. 86-99 ◽  
Author(s):  
I. Gardner ◽  
M. Theves
Keyword(s):  
Finite Element Analysis ◽  
Geometric Approach ◽  
Lateral Force ◽  
Slip Angle ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Slip Effects ◽  
Improved Accuracy ◽  
Nonlinear Geometric ◽  
Good Agreement

Abstract During a cornering maneuver by a vehicle, high forces are exerted on the tire's footprint and in the contact zone between the tire and the rim. To optimize the design of these components, a method is presented whereby the forces at the tire-rim interface and between the tire and roadway may be predicted using finite element analysis. The cornering tire is modeled quasi-statically using a nonlinear geometric approach, with a lateral force and a slip angle applied to the spindle of the wheel to simulate the cornering loads. These values were obtained experimentally from a force and moment machine. This procedure avoids the need for a costly dynamic analysis. Good agreement was obtained with experimental results for self-aligning torque, giving confidence in the results obtained in the tire footprint and at the rim. The model allows prediction of the geometry and of the pressure distributions in the footprint, since friction and slip effects in this area were considered. The model lends itself to further refinement for improved accuracy and additional applications.

Observer-Based Fault Diagnosis of Satellite Systems Subject to Time-Varying Thruster Faults

2006 ◽  
Vol 129 (3) ◽  
pp. 352-356 ◽  
Author(s):  
Wen Chen ◽  
Mehrdad Saif
Keyword(s):  
Fault Diagnosis ◽  
Estimation Error ◽  
Fault Estimation ◽  
Time Varying ◽  
Satellite Systems ◽  
Adaptive Observers ◽  
Error Dynamics ◽  
The Stability ◽  
Estimation Of Time ◽  
Identification Strategy

This paper presents a novel fault diagnosis approach in satellite systems for identifying time-varying thruster faults. To overcome the difficulty in identifying time-varying thruster faults by adaptive observers, an iterative learning observer (ILO) is designed to achieve estimation of time-varying faults. The proposed ILO-based fault-identification strategy uses a learning mechanism to perform fault estimation instead of using integrators that are commonly used in classical adaptive observers. The stability of estimation-error dynamics is established and proved. An illustrative example clearly shows that time-varying thruster faults can be accurately identified.

scholarly journals Fault Diagnosis for a Class of Robotic Systems with Application to 2-DOF Helicopter

2020 ◽  
Vol 10 (23) ◽  
pp. 8359
Author(s):  
Luis Alejandro Ramírez ◽  
Manuel Alejandro Zuñiga ◽  
Gerardo Romero ◽  
Efraín Alcorta-García ◽  
Aldo Jonathan Muñoz-Vázquez
Keyword(s):  
Fault Diagnosis ◽  
Original System ◽  
Research Area ◽  
Fault Detection And Isolation ◽  
Specific Class ◽  
Sensors And Actuators ◽  
Challenging Research ◽  
Classic Approach ◽  
Generalized Hamiltonian System ◽  
Two Degree Of Freedom

This paper considers a general approach to fault diagnosis using a generalized Hamiltonian system representation. It can be considered that, in general, nonlinear systems still represent a problem in fault diagnosis because there are results only for a specific class of them. Therefore, fault diagnosis remains a challenging research area despite the maturity of some of the available results. In this work, a type of nonlinear system that admits a generalized Hamiltonian representation is considered; in practice, there are many systems that have this kind of representation. Thereupon, an approach for fault detection and isolation based on the Hamiltonian representation is proposed. First, following the classic approach, the original system is decoupled in different subsystems so that each subsystem is sensitive to one particular fault. Then, taking advantage of the structure, a simple way to design the residuals is presented. Finally, the proposed scheme is validated at the two-degree of freedom (DOF) helicopter of Quanser®, where the presence of faults in sensors and actuators were considered. The results show the efficacy of the proposed scheme.

scholarly journals Fault-Structure-Based Active Fault Diagnosis: A Geometric Observer Approach

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4475
Author(s):  
Zhao Zhang ◽  
Xiao He
Keyword(s):  
Fault Diagnosis ◽  
Active Fault ◽  
Geometric Approach ◽  
Dynamic Equations ◽  
Fault Structure ◽  
Numerical Example ◽  
Input And Output ◽  
Incipient Faults ◽  
First Time ◽  
New Framework

Fault diagnosis techniques can be classified into passive and active types. Passive approaches only utilize the original input and output signals of the system. Because of the small amplitudes, the characteristics of incipient faults are not fully represented in the data of the system, so it is difficult to detect incipient faults by passive fault diagnosis techniques. In contrast, active methods can design auxiliary signals for specific faults and inject them into the system to improve fault diagnosis performance. Therefore, active fault diagnosis techniques are utilized in this article to detect and isolate incipient faults based on the fault structure. A new framework based on observer approach for active fault diagnosis is proposed and the geometric approach based fault diagnosis observer is introduced to active fault diagnosis for the first time. Based on the dynamic equations of residuals, auxiliary signals are designed to enhance the diagnosis performance for incipient faults that have specific structures. In addition, the requirements that auxiliary signals need to meet are discussed. The proposed method can realize the seamless combination of active fault diagnosis and passive fault diagnosis. Finally, a numerical example is presented to demonstrate the effectiveness of the proposed approach, and it is indicated that the proposed method significantly improves the accuracy of the diagnosis for incipient faults.

Study on Automated Manual Transmission Fault Diagnosis and Tolerant Control

2014 ◽  
Vol 697 ◽  
pp. 344-349
Author(s):  
Jian Bo Yin ◽  
Qi Chen ◽  
Yun Bo Ma ◽  
Yv Cai Zhao
Keyword(s):  
Mathematical Model ◽  
Fault Diagnosis ◽  
Manual Transmission ◽  
Sensors And Actuators ◽  
Information Redundancy ◽  
Matlab Simulink ◽  
Diagnosis Method ◽  
Automated Manual Transmission ◽  
Simulation Results ◽  
Engine Clutch

This paper discuss the possible fault about AMT. By using the information redundancy between those parts, the faults of sensors and actuators can be found. In addition, the corresponding tolerant is put forward. Based on the fault diagnosis method, Matlab/Simulink mathematical model of engine, clutch and transmission is built. The simulation results show that the model can satisfy the requirement of fault diagnosis, and has certain tolerances.

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